Muffler



Jan, 19, 1965 w. H. POWERS 3,166,151

MUFFLER Original Filed Sept. 18. 1957 2 Sheets-Sheet 1 X INVENTOR.

Jan. 19, 1965 w. H. POWERS 3,166,151

MUFFLER Original Filed Sept. 18'. 195'? 2 Sheets-Sheet 2 5 INVENTORUnited States Patent O 3,166,151 MUFFLER Walter H. Powers, Racine, Wis.,assigner to Walker Man-- ni'acturing Company, a corporation of DelawareOriginal applicaticn Sept. 18, 1957, Ser. No. 684,792, now Patent No.3,035,654, dated May 29, 1962. Divided and this appiication July 28,1961, Ser. No. 127,581 1 Claim. (Cl. 181-54) size of the muliier unit sothat it can be more readily placed in modern automobiles where space isat a premium.

The invention is illustrated in preferred forms in the accompanyingdrawings in .whichz FIGURE 1 is a longitudinal cross section through amuffler embodying the invention;

iFlG. 2 is a section taken along the line 2-2 of FIG. 1;

FIG. 3 `is a side elevation taken from the right of `FIG. l;

lFICi. 4 is `a longitudinal cross section of another muftler embodyingthe invention;

fFIG. 5 is a cross section taken along the line 5 5 of FIG. 4; and

FIG. 6 is a side elevation taken from the right of FIG. 4.

As seen in FlGS. 1 3, the rnuier 11 comprises an inner shell 101 whichis lockseamed at :103 and around which is wrapped a layer of asbestosand then an router cover 107 which is Ilockseamed at 109. The ends `ofthe shell 101 are closed by an outwardly bulged inlet header 111 and anoutwardly dished Ioutlet header 113 which are each interlocked with theends of the inner casing 101.

The space within the shell 101 is divided into chambers 1-15, i117, and.119 (which preferably occupies more than half the volume of the shell)Iby the two partitions 121 and 123 each of which has circumferentialanges extending toward the 'forward or inlet end head that are spotywelded to the shell 101. An inlet bushing 125 is expanded and spotwelded to a neck `127 on the inlet header 11|1 and -it also is seatedwithin a neck 129 of lthe partition y121 and spot welded to it, theinside end of the bushing 125 being iiared outwardly as shown at y131 tocatch behind the partition 121. In alignment with the opening providedyby the inlet bushing 125 but spaced from it across the width of thechamber 1,17 is an imperyforate tuning tube 133, the outlet end of thistube emptying into the resonator chamber 1-19 close to the outlet header113. It will be seen that gas flowing through .the tube -133 must returnthrough it back to the chamber 117. The outlet tube 135 is supported atits inlet end by spot welds which attach it to a forwardly extendingflange i137 on the partition 123. The .outlet end of the outlet pipe 135is spot welded to an enlarged diameter portion 13-9 on the drawn outletneck 141 formed in the outlet header 113. The outlet tube 135 has threegroups of louvers 143 formed in the wall thereof and extendingcircumferentially around it similar to the louvers 43. These louversempty into a series of spit chambers 145 which are separated from eachother and which surround each of the groups of louvers i143. The spitchambers 145 are provided by a pancake construction which con- ICC sistsof a pair of opposite stamped dished sheet metal sections which havemating flanges 149 that are spot welded together and which extendradially with respect to the axis of .the pipe. The ends of the sectionsare reduced so as to Atit the pipe 135 as seen at 151 andv153 andintermediate portions are also reduced so that they tit the pipe and arespot welded to it as seen at 155. A. hanger strap 157 is spot welded at159 to the tiange 149 of the pancake construction 1147 and its other endis spot welded at 161 to the outlet end of the tuning tube i133 so as tofurnish support for it and eliminate the need for a partition to[furnish such support.

The partition 121 has a pair of necked openings 163 and 1165 whichcommunicate the chamber i117 with the chamber 115. The partition121'will serve to eliminate head ring at the inlet end of the mufflerand the small volume provided there, largely :because .of the `outwardlydished shape of the inlet header 111, will serve to attenuate certainfrequencies.

The gas will enter .the muiiier =11 through the inlet bushing 125 fromthe pipe 9 and flow through it into the chamber :1117. This gas can owtransversely of the length of the muffler across the space 1:17 andenter the inlet end of the outlet pipe and iiow through it directlythrough the mufer 11 into the tail pipe (not shown). However, heavynotes and heavy slugs of gas will pass through the tuning tube 133 andenterjthe dead end chamber 119 and be attenuated there.y Additionalsilencing is obtained in the spit chambers and in the chamber 115.

The partitions 121 and 123 have the internal drainage openings 17 formedadjacent to the shell 1011 at the top and the bottom of the muffler, itbeing noted that this muier is disposed so that the major axis isvertical. The openings 1.71 should be approximately 1A in diameter. Theoutlet header :113 also may have a 0.12 diameter opening `on its bottomside as shown at '173, it being noted that FIG. 3 shows the -rnutiierturned upside down from the position that it would be used.

FIGS. 4-6 show a modied mutiier construction 299. The muffler I261% hasan inner shell 201 which isV lockseamed at 263. It is surrounded by alayer of asbestos 205 which in turn is held in place :by a cover 207that is lockseamed at 269. The inlet header 211 is bulged outwardly andinterlocked in a reverse bend joint at 213 while the `outlet header 215is also interlocked with the shell 201 in reversely bend bead 217.

The inlet header 211 has an outwardly extending flanged neck 214. Seatedin the neck 2.14 is an inlet bushing 2416 which is expanded at oppositesides of the neck 214 and .into tight engagement with :the neck s0 thatit can be spot welded to the neck. The end of the bushing 216 extendsthrough a rearwardly .facing neck 219 formed in a transverse partition221 that has a circumferential ange that is spot welded to the shell2&11. Within the outlet end of the bushing 216 is mounted a tuning tube`225 and it along with the bushing 216 are spot welded to the neck 219as seen at 227. The partition 221 forms a chamber 229 Ibetween it andthe inlet header 211 which is preferably less than half the volume ofthe shell 2011. Gas entering the muffler through the inlet bushing 216can enter the chamber 2129 Without resistance because of a very largeand non-restrictive opening 231 which is cut in the side of the bushing216. The tube 225 is im-perforate and extends along the length of themutiler and terminates in an open end near the outlet header 215. Thus,gases which enter it will be dumped into a chamber 233 which is formedbetween the outlet header 215 and a transverse partition 235 which isprovided with a circumferential dlange whereby it may be spot welded tothe inside of the .shell i201. The space between the partition I235 andthe partition 221 constivon the partition 221 and its outlet end issupported and spot Welded to a drawn neck or nipple 245 formedintegrally with the outlet header 215. The outlet pipe 241 is providedwith three sets of louvers 247 and these are surrounded by a pancakeassembly formed of cornplemental halves which have radial tlanges 251which are spot Welded together along a medial plane and which are neckeddown appropriately to provide sections 253 at opposite ends which arespot welded to the circumference of the ltube 241 and intermediateVnecked down sections 255 which are also spot Welded to the circumferenceof the tube. The assembly `249 provides the spit chamber 257 which actupon sound Waves reaching it through the louvers 247 -to attentuate highfrequencies in a known manner. The intermediate partition 235 isprovided with a flanged opening 260 through which the pancake assembly249 extends and upon which it is supported as can be seen in FIGS. 4 and5.

Gas entering the muler 200 through the inlet nipple 216 can oW throughthe very large unrestricted opening 231 transversely across chamber 229into the outlet pipe V241 and down its length out of the muler into thetail pipe 13. While passing along the pipe 241 high frequency soundsWill be attenuated in thethree spit chambers 257. YHeavy notes and largeslugs of gas Will pass from the inlet bushing 216 directly along fthealigned tuning tube 225 into the chamber 233 and through neck 239 intochamber 237 Where they Will be attenuated. It Will be seen that thepanticular construction of the inlet v nipple 216 provides a rigid mulereliminating the need for a partition.

The partitions 221 and 235 have the drainage holes 261 formed on the topand bottom thereof adjacent the shell 201. These should be M1." indiameter to avoid plugging and to avoid affecting the acousticcharaoterisitcs of the muiiler. These holes Will permit the Water toiiow longitudinally from one chamber to another as the muler is rockedin usage thus permitting the condensate to come in contact with hotgases, be vaporized, land carried out through the outlet pipe. At thebottom of the outlet header 215 a 0.12" diameter drainage opening 263 isformed, this size being small enough so that it does not adverselyatleet the acoustic characteristics of the muffler.

This application is a division of my copending application, Serial No.684,792, tiled September 18, 1957, now Patent No. 3,036,654 issued May29, 1962.

l I claim:

A small muiiler for use as a second silencing component in an internalcombustion engine exhaust lline to silence a very low frequency and veryhigh frequencies, said muffler comprising an elongated casing havinginlet and outlet headers closing opposite ends, said casing having atransverse partition extending thereacross located close to the inletheader and dening an inlet chamber at the inlet end of the casing,v saidtransverse partition and said outlet header defining a large resonatorchamber inside said casing which extends substantially more than halfthe length of the casing, a long open-ended outlet conduit extendinglongitudinally through the resonator chamber and having its outlet endsecured in said outlet header and its inlet end secured in saidtransverse partition, said outlet conduit receiving all of its gas lioiwfrom said inlet chamber, a portion of said outlet conduit inside saidresonator chamber being perforated, animperforate shell around theentire perforated portion of said outlet conduit Vin said resonatorchamber to dene with said perforated portion a series of high frequencysilencing chambers inside of the resonator chamber, a long open-endedimperforate tuning tube secured at its inlet end in said transversepartition and extending longitudinally through said resonator chamberand terminating near the outlet header, said tuning tube having a lengthmore .than half that of the casing, said tuning tube receiving itsrentire gas ilow from said inlet chamber and returning its entire flowto said inlet chamber, said tuning tube and resonator chamber forming avery loW frequency silencing means, and an inlet bushing in said inletheader delivering the entire exhaust gas flow to said inlet chamber.

References Cited in the le of this patent UNITED STATES PATENTS1,603,910 Egner Oct. 19, 1926 v 1,821,688 Bourne Sept. 1, 1931 2,026,795Oldberg Ian. 7, 1936 2,027,359 Wood et al Jan. 7, 1936 2,065,232MacKenzie et al a 1 Dec. 22, 1936 2,160,332 Huber May 30, 1939 2,189,425Leadbetter vFeb. 6, 1940 2,205,899 Chipley lune 25, 1940 2,297,046Bourne Sept. 29, 1942 2,671,523 Walker Mar. 9, 1954 2,851,118 Diener etal Sept. 9, 1958 2,930,440 Fetzer et al Mar. 29, 1960 2,949,165 Morrishet al Aug. 16, 1960 2 950777 Deremer Aug. 30, 1960

